Gore Bike Wear Men's Windstopper  Base Layer Turtleneck Top Shell: 100% Polyester; Windstopper Membrane, Stretch: 92% Polypropylene, 8% Elastane Imported Windproof long-sleeve turtleneck shirt with front zipper is ideal for windy and cold days. Provides warmth and quick moisture management. Protects from cooling at neck, breast, shoulder, arm and kidney area. Tight fit Elastic WINDSTOPPER insert on front, at sleeves, over shoulders and on kidney area Thermo-stretch functional fabric Minimized seams for less chafing Flat-lock seams Close fit collar